Composite electrode for electronic animated advertising sign system



Jan. 18, 1955 R H SEAMAN 2,700,117

COMPOSITE ELECTRODE FOR ELECTRONIC ANIMATED ADVERTISING SIGN SYSTEM Filed Jan. 16, 1951 2 Sheets-Sheet 1 INVENTOR. QSea/wwvvv 2 NM NE OT RS T Y CS E mm MFG A N ET- RT mm RE A E D T E Jan. 18, 1955 COMPOSI ANIMAT 2 Sheets-Sheet 2 Filed Jan. 16, 1951 ilnite tates Patent O COMPOSITE ELECTRODE FOR ELECTRONIC ANIMATED ADVERTISING SIGN SYSTEM Richard H. Seaman, Los Angeles, Calif., assignor to Mega Corporation, Los Angeles, Calif., a corporation of California 3 Claims. c1. 313-117 My invention relates broadly to electronic animated advertising sign systems and more particularly to a construction of a composite electrode for use in such systems.

This application is a division of my application Serial Number 758,659 filed July 2, 1947, now Patent 2,568,767, dated September 25, 1951, for Electronic Animated Advertising Sign System.

One of the objects of my invention is to provide a construction of composite cathode and anode for installation in the opposite terminal ends of luminous discharge tubes used in electronic animated advertising sign systems.

Still another object of my invention is to provide a construction of composite cathode and anode for luminous discharge tubes in which the cathode is substantially shielded with respect to visual light emission while effecting electronic emission for ionizing the discharge path through the tube with respect to a symmetrically arranged terminal cathode and anode device.

Still another object of my invention is to provide an improved construction of composite cathode and anode for symmetrical installation in the opposite interior terminal ends of gaseous discharge tubes forming an animated design system in which each composite electrode includes a cathode portion and an anode portion and an intermediate shield for preventing the visual eifects of the cathode portion from interfering with the luminous discharge incident upon the anode portion from the cathode portion of the opposite remote-terminal electrode.

Still another object of my invention is to provide symmetrical constructions of terminal cathode and anode device for luminous discharge tubes located at the opposite terminal ends of luminous discharge tubes in which the anode of one composite electrode coacts with the cathode of the opposite composite electrode in alternation with the coaction with the cathode of the first mentioned composite electrode with the anode of the second mentioned composite electrode for producing a high ionized path through a gaseous discharge tube.

A still further object of my invention is to provide a construction of composite cathode and anode device for the terminal ends of gaseous discharge tubes including a multiplicity of intermediate spaced anodes wherethe intermediate anodes are arranged to function in coaction with the cathodes in the terminal ends of the gaseous discharge tube in alternation and with the anodes of the terminal electrodes coacting with the cathodes of the opposite terminal electrodes in succession for producing a high ionized luminous discharge path through the tube.

Other and further objects of my invention reside in the novel construction of composite cathode and anode for the'opposite interior ends of gaseous discharge tubes as set forth more fully in the specification hereinafter following by reference to the accompanying drawings in which:

Figure '1 is a longitudinal cross-sectional view through a gaseous discharge tube forming part of an animated advertising sign system, the view being foreshortened by illustrating the arrangement of the intermediate anodes in spaced positions along the tube; Fig. 2 is a side elevational view of the tube shown in Fig. 1, the view being foreshortened in a manner similar to that illustrated in Fig. 1; Fig. 3 is an enlarged longitudinal sectional view tube.

the cathode and anode in the terminal end of the tube and showing one of the intermed1ate anodes; Flg. 4 is a transverse sectional view taken on line 44 of Fig. 3

and illustrating the tubular enclosure for the composite electrode in elevation; Fig. 5 is a transverse sectional view taken on line 5-5 of Fig. 3; Fig. 6 is a transverse sectional view taken on line 6-6 of Fig. 3; Fig. 7 is a longitudinal sectional view through a modified form of gaseous discharge tube embodying my invention; and Fig. 8 is a side elevational view of the form of tube shown in Fig. 7.

The composite cathode and anode of the gaseous discharge tube of my invention has been developed to meet the need for effecting intense ionization of the gaseous discharge path through the tubular envelope of an animated advertising sign system where the direction of ionization is alternately changed through the discharge path in the tube. The abrupt change of direction of discharge is produced by alternate change of eit'ective polarity in the opposite ends of the coacting tubes. The composite cathode and anode devices each include a cathode portion and an anode portion with means for shielding the cathode portion from an appreciable visual emission sufiicient to interfere with gaseous discharge through the The tubular envelope intermediate the terminal ends of the device contains a multiplicity of spaced anodes with which the cathode of one composite electrode coacts during one cycle of energization and wherein the cathode of the opposite terminal electrode coacts during the succeeding cycle. That is to say, the luminous discharge path through the tube reverses in direction with the cyclic change of the alternating current impressed power supply thereby increasing the effective ionization of the discharge paths and correspondingly increasing the brilliance of illumination. As more fully explained in my application Serial Number 758,659 filed July 2, 1947, now Patent 2,568,767, dated September 25, 1951, for Electronic Animated Advertising Sign System of which this application is a division, the operation of the discharge tube of my invention in the production of illuminated writings or animations requires the maintenance of travelling dark spaces through the tube in relation to the travelling luminous discharge through the tube, inasmuch as the composite electrodes in the terminal ends of each of the tubes must be maintained in a continuous state of activation. The incandescence of a hot cathode necessary to maintain electronic discharge through the tube which must be alternately dark or luminous produces visual rays which interfere with the display of the tube. Accordingly in the structure of my invention I provide means for shielding the cathode against appreciable visual emission while enabling electronic discharge to be effected for ionizing the discharge path through the tube. The structure of the composite cathode and anode devices is symmetrical for each end of the tube and the dimensions of the composite electrodes is such that the composite electrode portions of the tube may form mounting means for the opposite ends of the luminous display portion of the tubular envelope thus facilitating the assembly of a multiple number of such tubes in various configurations and designs.

Referring to the drawings in detail I have shown the tubular envelope 31 enclosing a multiplicity of spaced anodes represented at 1, 2, 3, 4, 5, etc. electrically connected through leads 1a, 2a, 3a, 4a and 5a sealed in a gas-tight manner in the side wall of the envelope 31 with the control circuit means set forth more fully in my application 758,659 of July 2, 1947, now Patent 2,568,767, dated September 25, 1951, supra. At opposite ends of the tubular envelope 31 I provide tubular enclosures 11 and 12 extending on axes substantially normal to the longitudinal axis of the tubular envelope 31 and forming a gas-tight joint with the tubular envelope 31 at 11a and 12a.

The tubular enclosures 11 and 12 each carry press supports 14 and 15 for securing the leads 16, 17 and 18 and 19, 20 and 21 in terminal positions at opposite ends of the tube. The leads 16 and 18 support the cathode 34 in a substantially lateral position at one end of the tube while the lead 17 supporting the visual shield, or

sleeve-like electrode or shell 36 that surrounds the cathode 34. The visual shield or sleeve-like electrode or shell 36 surrounds the cathode 34 and serves as a support for the disc-like electrode or anode 41 through extension strip members 40 and 40a. The disc-like electrode 41 in coaction with the shell 36 serves as an anode surface and also as a light shield to prevent appreciable visual light rays from illuminating the ends of the tube during the inactive or dark space period of operation of the tube. The disc-like electrode 41 is suificiently spaced from the inner walls of the gaseous discharge tube to allow for the discharge of electrons from the electron generator constituted by filament 3 3 in a stream extending longitudinally of the vessel in a path across anodes 1, 2, 3, etc. When the composite cathode and anode device operates as an anode the surface of disclike electrode 41 is bombarded with electrons and serves as a collector of electrons under conditions where the potential of cathode 34-, shell 36 and disc-like electrode 41, go positive. Under conditions where the polarity of the potential reverses, the cathode 3d, shell 36 and disclike electrode 41 becomes negative instead of positive and serves as a generator or electron discharge electrode.

Without the interposition of the transversely extending disc-like electrode 41 the incandescent cathode 34 would be clearly visible when viewed from the front of the tube and very substantially impair the display obtainable when a multiplicity of such tubes are conjointiy assembled in a display sign.

The opposite end of the tube is constructed in a manner similar to the terminal end in enclosure 11 as already explained. In the terminal end within enclosure 12 the leads l9 and 21 support the cathode 42 in a substantially transverse position. The lead 20 supports the visual light shield, sleeve-like electrode or shell 43 which surrounds the cathode 42. The visual light shield, sleevelike electrode or shell 43 supports disc-like electrode or anode 44 through extension strip members 45 and 450 at a sufiicient distance from the cathode 42 to permit discharge of electrons around disc-like electrode or anode 44 and through the longitudinally extending discharge path 46 within the gaseous discharge tube 31.

In each instance the visual shield or sleeve-like electrode or shell 36 and 43 is electrically connected to the disc-like electrode or anode 41 and 44 respectively so that the entire conductive area of the visual shield, sleevelike electrode or shell forms with the associated disclike electrode the anode surface forming a collector of electrons in coaction with the cathode of the remote composite electrode in the opposite interior end of the gaseous discharge tube. That is to say, the anode area comprising visual shield or sleeve-like electrode or shell 36 and disc-like electrode 41 conjointly serve as an anode area or target with respect tocathode 42 in the remote end of the gaseous discharge tube whereas visual shield, or sleeve-like electrode or shell 43 and the associated disclike electrode 44 serves as an anode area or target with respect to the cathode 34 in the opposite remote end of the gaseous discharge tube. Similarly the intermediate anodes 1, 2, 3, 4-, 5, etc. serve as targets or collectors during one half of a cycle with respect to cathode 36 and during the other half of the cycle with respect to cathode 42 as set forth more fully in my application 758,659 now Patent 2,568,767, supra. The ends of the gaseous discharge tubes are constructed in a sym- I metrical manner so that the transverse plane of disc-like electrode or anode i1 is substantially coplanar with the transverse plane of the disc-like electrode or anode 44 and the spacial distances of cathodes 36 and 42 form the longitudinal axis of the discharge path 46 through the envelope 311 are substantially the same'and also the visual 'shields or sleeve-like electrodes or shells 36 and 43 have the same cylindrical linear lengths and are substantially aligned with respect to each other at opposite terminal ends of the tube.

In Figs. 7 and 8 I have shown a modified form of my invention in which the composite electrodes are mounted on the same longitudinal axis through the length of the tube. In this arrangement the connections to the composite electrodes are established with the opposite ends of the tube in line with the longitudinal axis of the tube and in certain instances this arrangement may be more compact than in the arrangement illustrated in Figs. 1-6 where the electron generators are disposed on axes substantially normal to the longitudinal axis of the envelope. All of the detailed arrangements of the components of the composite electrodes and the arrangements of the intermediate anodes are the same as already explained in connection with Figs. 1-6 so that the same reference characters used in Figs. 1-6 have been used in the arrangement shown in Figs. 7-8.

, It will be understood that visual rays from the incandescent electrodes 34 and 42 are prevented from interfering with the glow discharge through the glow portion of the tube by the arrangement of light shields 36 and In the form of my invention shown in Figs. 7 and 8, the anode or target electrodes 41 and 44 are dis posed in spaced substantially parallel planes on opposite sides of the series of intermediate anodes l, 2, 3, 4, 5, etc. The views, Figs. 7 and 8, have been foreshortened in order to indicate that the tubes may be of very substantial length. In certain instances it may be desirable to enlarge the end portions of the envelope which house the composite electrodes and seal these to opposite ends of the glow discharge portion of the tube which may be of smaller-diameter than the end sections which house the composite electrodes, For simplifying the illustration of my invention I have omitted the conventional connection for exhausting or introducing gas into the tubular envelope.

The structure of each of the composite electrodes is very substantial and rugged and has been found to be very effective in operation. I realize, however, that modifications in the structure of my invention may be made and I desire that it be understood that no limitations upon my invention are intended other than may be imposed by the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States is as follows:

.1. In a luminous discharge tube, an elongated envelope, a composite cathode and anode electrode disposed in each end of said envelope, a multiplicity of spacially disposed anodes arranged intermediate said composite electrodes, said composite cathode and anode electrodes each including a heated luminous electronic discharge device, a cylindrical shielding member substantially surrounding said disharge device, a target anode member disposed intermediate said discharge device and said spacially disposed anodes, and means for conductively supporting said target anode member on said cylindrical shielding member as an extension thereof in spaced relation thereto as a unit for discharge of electrons from said luminous cathode in one end of said envelope to said spacially disposed anodes in a path intermediate said shielding member and said target anode member in said end of said envelope, said composite cathode and anode electrode in the other end of said envelope being symmetrically disposed with respect to said specially disposed anodes, each of said shielding members substantially blocking visual ray emanations from said luminous cathodes when viewed from the luminous discharge path,

between said spacially disposed anodes.

2. A luminous discharge tube as set forth in claim 1, in which the means for conductively supporting said target anode member on said cylindrical shielding member comprise extension strip members ofiering inappreciable obstruction to the discharge of electrons from said cathode and around the peripheral edges of said target anode member.

3. A luminous discharge tube as set forth in claim 1 in which the means for conductively supporting said target anode member on said cylindrical shielding member comprise a pair of extension strip member's disposed in diametrically opposite positions and providing a substantially free space path for the discharge of electrons at each of the sides thereof around the peripheral edges of said target anode member.

References Cited in the file of this patent UNITED STATES PATENTS 1,877,932 Meyer Sept. 20, 1932 1,878,502 Mailey Sept. 20, 1932 1,958,239 Found May 8, 1934 2,061,390 Stevens Nov. 17, 1936 2,114,535 Kirsten Apr. 19, 1938 2,398,647 Keller Apr. 16, 1946 

